1. The hair on a man's cheeks and chin. 2. A single hair of a beard or mustache. 3. One of the long stiff tactile bristles or hairs that grow near the mouth and elsewhere on the head of most mammals; a vibrissa. 4. The candidate lost the election by a whisker. 5. One of two spars or booms projecting from the side of a bowsprit for spreading the jib or flying-jib guys. 6. An extremely fine filamentary crystal with extraordinary shear strength and unusual electrical or surface properties.
